From Before I Play
- Take your time, explore, soak up the atmosphere. It rewards exploration and you're missing out if you don't poke around - especially in the stations.
- The revolver is a very reliable weapon and can take you through the entire game, though not worth silencing. If you're killing people stealthily the throwing knives are a much better option anyway.
- Listen to NPC chatter. Seriously: the stories they tell are absolutely beautiful at times, and really draw you in.
- Early on you get a chance to spend some time with a prostitute. Don't do this unless you want to lose all your money.
- Buy SHITLOADS of ammo at every shop (but when a dude tells you to buy gas mask filters, get those first)
- Helsing gun is very powerful and has reusable ammo - you pretty much need it to finish the game as one part has a lot of strong enemies that simply suck up ammo.
- Throwing knives, if you score a good hit with them, will stealthily instakill most enemies and you can pick the knife back up. Don't forget about them.
- Long-range scopes are practically useless - you never fight at a range that will require sniping.